Local area networks, or LANS, are used to transmit packetized data. One type of LAN is known as the Ethernet which conforms to a family of IEEE standards, IEEE 802.3. Although Ethernet LANs have been produced for over 20 years, recent technological advances have increased the speed at which devices connected to the ethernet LAN can transmit and receive data. In IEEE draft standard 802.3z an Ethernet LAN capable of gigabit per second transmission rates is proposed. However, one limitation of current ethernet LANs is that they must limit the distance between devices to about 2 km, in order to allow their carrier-sense multiple-access collision-detection (CSMA/CD) contention management systems to function effectively. A description of local area networks is found in the textbook Basic Data Communications: A Comprehensive Overview by W. J. Beyda which is hereby incorporated by reference for all purposes.
Data transmitted over a LAN is packetized or subdivided into a stream of segments of varying length. Packet flow is often described as "bursty". Packets may flow intensely between two devices connected to the LAN and then flow may suddenly drop to zero. When packets flow intensely from a number of different devices simultaneously, contention problems may arise and it is necessary to share the bandwidth on the LAN between contending devices.
It would be desirable for devices connected to an ethernet LAN to be able to transmit data to or receive data from devices connected to separate ethernet LANS. In this regard, it is known to use expensive special purpose wide area network (WAN) routers interposed between LANs.